1. Field of the Invention
The present invention relates to hand tools, and more particularly to reversing ratchet wrenches from use with interchangeable socket heads.
2. Description of the Background
Reversing ratchet wrenches are widely used to apply torque for tightening or loosening nuts and bolts. Conventional wrenches include an elongated handle formed with a head at one end for housing the ratchet mechanism. A ratchet driver is rotatably mounted within the housing in engagement with a toothed pawl. The pawl is selectively engagable by operation of a reversing lever into two driver engaging positions in which the driver is limited to one of clockwise or counterclockwise rotation.
The utility of such wrenches largely depends on the design of the reversing ratchet mechanism and the machined head in which it is seated. The design objectives include simplicity and improved manufacturing economy, ease of use, higher strength and durability, conservation of space, protection of internal components, protection of the external reversing lever, and ease of disassembly and repair.
U.S Pat. No. 2,978,081 is one example of a ratchet wrench which conserves space while maintaining durability. However, the machining operations necessary to produce the intricate pawl and driver preclude cost-effective mass production.
U.S. Pat. No. 4,277,990 discloses a wrench of simpler design which is more suitable for mass production. However, this wrench is exceedingly difficult to disassemble for repairs.
U.S. Pat. No. 4,485,700 discloses a wrench design which attempts to minimize both space and cost of manufacture. However, the design incorporates a split ring retainer which hinders disassembly. In addition, both the driver cap and the reversing lever protrude from the wrench head. Consequently, a mechanic cannot easily grip the wrench head to apply pressure while turning. Moreover, the unprotected reversing lever is susceptible to being sheared off and/or inadvertent shifting. The wrench is also prone to clogging by grit and particulates which are drawn between the exposed bearing surfaces.